U.S. patent application number 14/395152 was filed with the patent office on 2015-03-05 for coil unit and electric vehicle.
The applicant listed for this patent is CONDUCTIX-WAMPFLER GMBH. Invention is credited to Pascal Asselin, Andrew Green, Mathias Wechlin.
Application Number | 20150061593 14/395152 |
Document ID | / |
Family ID | 47633068 |
Filed Date | 2015-03-05 |
United States Patent
Application |
20150061593 |
Kind Code |
A1 |
Wechlin; Mathias ; et
al. |
March 5, 2015 |
COIL UNIT AND ELECTRIC VEHICLE
Abstract
A coil unit for an electric vehicle for the inductive transfer
of electrical energy between the coil unit and a stationary
charging station. The coil unit includes at least one coil and a
flux guide unit for guiding a magnetic flux occurring during
operation of the coil. Also disclosed is an electric vehicle having
a coil unit for the inductive transfer of electrical energy between
a secondary coil of the coil unit and a primary coil of a charging
station. The disclosed coil solves the problem of allowing the safe
use of the inductive electrical energy transfer in electric
vehicles, in particular motor vehicles, by proposing a coil unit,
in which the flux guide unit has material weakenings, and an
electric vehicle having such a coil unit.
Inventors: |
Wechlin; Mathias; (Kandern,
DE) ; Asselin; Pascal; (Riedisheim, DE) ;
Green; Andrew; (Malsburg-Marzell, DE) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
CONDUCTIX-WAMPFLER GMBH |
Weil am Rhein |
|
DE |
|
|
Family ID: |
47633068 |
Appl. No.: |
14/395152 |
Filed: |
February 1, 2013 |
PCT Filed: |
February 1, 2013 |
PCT NO: |
PCT/EP2013/052016 |
371 Date: |
October 17, 2014 |
Current U.S.
Class: |
320/109 ;
336/233 |
Current CPC
Class: |
H01F 3/00 20130101; B60L
53/12 20190201; Y02T 10/70 20130101; Y02T 90/14 20130101; Y02T
90/12 20130101; Y02T 10/7072 20130101 |
Class at
Publication: |
320/109 ;
336/233 |
International
Class: |
H01F 3/00 20060101
H01F003/00; B60L 11/18 20060101 B60L011/18 |
Foreign Application Data
Date |
Code |
Application Number |
Apr 17, 2012 |
DE |
10 2012 103 315.3 |
Claims
1. Coil unit for an electric vehicle for the inductive transfer of
electrical energy between the coil unit and a stationary charging
station, wherein the coil unit has at least one coil and a flux
guide unit for guidance of a magnetic flux appearing during the
operation of the coil, wherein the flux guide unit has material
weaknesses.
2. Coil unit according to claim 1, wherein the material weaknesses
essentially run transverse to the longitudinal direction of the
vehicle.
3. Coil unit according to claim 1, wherein the material weaknesses
essentially run concentric to a center of the flux guide unit.
4. Coil unit according to claim 1, wherein the material weaknesses
essentially run in the direction of the magnetic field lines of the
magnetic flux guided in the flux guide unit.
5. Coil unit according to claim 1, wherein the material weaknesses
are designed, completely or partially, as predetermined breaking
points.
6. Coil unit according to claim 1, wherein the material weaknesses
in the flux guide unit are provided grooves.
7. Coil unit according to claim 1, wherein the material weaknesses
are provided on different flat sides of the flux guide unit.
8. Coil unit according to claim 1, wherein the material weaknesses
are alternatingly provided on the different flat sides of the flux
guide unit.
9. Coil unit according to claim 1, wherein the material weaknesses
run in a plane of the flux guide unit, parallel to the longitudinal
direction of the vehicle, at an incline, preferably, at an incline
to plane.
10. Coil unit according to claim 1, wherein the material weaknesses
are partial or complete breaks of the flux guide unit.
11. Coil unit according to claim 9, wherein the breaks are,
partially or completely, filled with an adhesive and/or bonding
material.
12. Coil unit according to claim 11, wherein the adhesive and/or
the bonding material has ferromagnetic or ferrimagnetic
characteristics.
13. Electric vehicle with a coil unit for the inductive transfer of
electrical energy between a secondary coil of the coil unit and a
primary coil of a charging station, wherein the coil unit is
designed in accordance with claim 1.
Description
[0001] The invention concerns a coil unit according to the preamble
of Claim 1 and an electric vehicle according to the preamble of
Claim 13.
[0002] In the area of the transfer of inductive energy to movable
consumers, for example, electric land vehicles, such as automobiles
or trucks, a method is known for charging its vehicle battery via a
stationary primary coil of a charging station and a secondary coil
located on the bottom of the vehicle. The primary coil is thereby
located on or in the traveling lane, for example, on publicly
accessible parking lots, charging areas of filling stations, or in
the garage of the owner of the vehicle. For the charging operation,
the electric vehicle is driven over the primary coil, so that the
secondary coil that is located in the vehicle is aligned on the
primary coil.
[0003] DE 10 2009 033 236 A1 discloses an example for this, in
which the secondary coil is located, together with a ferrite plate
as a flux guide unit, in a housing on the bottom of an electric
vehicle.
[0004] DE 10 2008 029 200 A1 discloses a body of a motor vehicle
with at least one structure area formed from a plate element. The
plate element is located on the bottom of the vehicle body and, in
the longitudinal direction, has longitudinal hollow chambers
located in the transverse direction of the motor vehicle, next to
one another, into which energy storage elements, in particular,
accumulator batteries, or other components of an energy storage
device are placed. In order to reduce damage or destruction of the
energy storage device with the resulting endangerment of the
vehicle occupants in case of an accident of the motor vehicle, the
energy storage elements, for example, are located only in areas
which cannot be deformed excessively in case of an accident, for
example, only under the driver's seat, located centrally. In this
way, not only the front and rear structures, but also the lateral
areas of the passenger compartment, can be deformed for the energy
absorption, whereas the energy storage elements are not located in
these areas.
[0005] DE 10 2007 040 770 A1 discloses a passenger car with a
vehicle bottom with a middle tunnel, which extends in the
longitudinal direction of the vehicle. The middle tunnel has at
least one weak site, where the middle tunnel is deformed under the
effect of force caused by an accident after a stress limit has been
exceeded. No indication is made there of a coil unit with a flux
guide unit for the inductive transfer of electrical energy between
the coil unit and a stationary charging station.
[0006] DE 10 2010 035 634 A1 discloses a transfer system for
charging the traction batteries of an electric vehicle with a
coupling device that is attachable thereon, with a transformer
part, by means of which the electrical energy can be transferred
inductively to a transformer part on the vehicle. The transformer
part, which is integrated in the vehicle license plate, has a
coupling body made of a flexible plastic material, which surrounds
an electrical coil arrangement with a ferrite arrangement,
consisting of plate- or yoke-like ferrites, separated from one
another. The ferrites, separated from one another, worsen the
magnetic flux guidance and thus the coupling between the
transformer parts.
[0007] With the known coil units, the disadvantage is that the
magnetic flux guide unit, as a rule, is made of a massive, rigid,
and heavy material, for example, a ferrite plate. Since the coil
unit is usually arranged, parallel to the surface, on the bottom of
the vehicle and exhibits a great inertia because of its heavy
weight, the danger with a rear-end collision is that the flux guide
unit will be hurled in the direction of the impact zone and the
coil unit will be thereby destroyed and perhaps travel from its
anchorage on the bottom of the vehicle and will damage the vehicle
and endanger the vehicle occupants as well as persons found outside
the vehicle. Since the flux guide unit is also very rigid, as a
rule, it will also transfer the impact energy, more or less
undiminished, in case of a collision.
[0008] The goal of the invention under consideration is to overcome
the aforementioned disadvantages and to make available a coil unit
and electric unit, mentioned in the beginning, which make possible
the safe use of the inductive electrical energy transfer with
electric vehicles, in particular, motor vehicles.
[0009] This goal is attained by the invention with a coil unit with
the features of Claim 1 and an electric vehicle with the features
of Claim 13. Advantageous developments and appropriate refinements
of the invention are indicated in the subclaims.
[0010] A coil unit mentioned in the beginning is characterized, in
accordance with the invention, in that the flux guide unit exhibits
material weaknesses.
[0011] Preferably, the material weaknesses can essentially run
transverse to the longitudinal direction of the vehicle, where this
includes slight deviations by a few centimeters, preferably, by a
few millimeters, from the course exactly transverse to the
longitudinal direction. Preferably, the material weaknesses can
also run essentially concentric to a center of the flux guide unit.
Also preferably, the material weaknesses can essentially run in the
direction of the magnetic field lines of the magnetic flux guided
in the flux guide unit, so that the magnetic flux is hardly
impaired in the flux guide unit.
[0012] In an advantageous development of the invention, the
material weaknesses can be designed, completely or partially, as
predetermined breaking points, so that in case of an accident, the
impact energy damages or completely destroys the predetermined
breaking points.
[0013] In an embodiment which is favorable for manufacturing
technology, the material weaknesses in the flux guide unit can be
provided as grooves. Furthermore, the material weaknesses can be
provided on various flat sides of the flux guide unit so they are
favorable for operational technology, in order to reduce a
deformation of the flux guide unit in a preferred direction.
[0014] Preferably, the material weaknesses can run in a plane of
the flux guide unit, parallel to the longitudinal direction of the
vehicle, inclined--preferably, at an incline to the plane. Thus,
parts of the flux guide unit, broken apart in case of an accident,
do not collide against one another with their impact edges and in
this way, transfer the impact energy, but rather the parts of the
flux guide unit, which have broken part, are pushed from the plane
against one another--that is, they move past one another.
[0015] Preferably, the material weaknesses can be partial or
complete breaks of the flux guide unit. In a favorable embodiment,
the breaks can be filled, partially or completely, with an adhesive
and/or bonding material, so that they are affixed to one another,
in their position. The adhesive and/or the bonding material can
thereby have ferromagnetic or ferrimagnetic characteristics, so as
to make available a good magnetic conductance and thus a good flux
guidance in the flux guide unit in spite of the breaks.
[0016] An electric vehicle, mentioned in the beginning, is
characterized, in accordance with the invention, in that the coil
unit is designed as described above and below.
[0017] Embodiment examples of the invention are described in
detail, below, with the aid of the appended drawings. The figures
show the following:
[0018] FIG. 1, a lateral sectional view of an inductive energy
transfer device with a first embodiment of a coil unit in
accordance with the invention;
[0019] FIG. 2, a schematic top view of the coil unit from FIG.
1;
[0020] FIG. 3, a lateral sectional view of a second coil unit in
accordance with the invention;
[0021] FIG. 4, a lateral sectional view of a third coil unit in
accordance with the invention;
[0022] FIG. 5, a lateral sectional view of the coil unit from FIG.
4, after it was destroyed;
[0023] FIG. 6, a lateral sectional view of a fourth coil unit in
accordance with the invention;
[0024] FIGS. 7 a-c, schematic top views of other coil units in
accordance with the invention, with a circular disk-shaped flux
guide unit;
[0025] FIGS. 8 a-c, schematic top views of other coil units in
accordance with the invention, with a square flux guide unit.
[0026] FIG. 1 shows, schematically, a lateral sectional view of an
energy transfer device 1 for the inductive transfer of electrical
energy between a primary coil unit 3, installed on a lane bottom 2,
which is, in fact, known, and a secondary coil unit 6 in accordance
with the invention, placed on a vehicle bottom 4 of an electric
vehicle 5. The longitudinal and forward traveling direction of the
electric vehicle 5 is marked with an arrow L in FIG. 1.
[0027] The primary coil unit 3 thereby comprises, in a manner which
is, in fact, known, a primary coil housing 7 with a primary coil 8
located therein, with primary coil windings 9 and a primary
coil-flux guide unit 10.
[0028] The secondary coil unit 6, which is also only designated,
below, as the coil unit 6, has--in a manner which is, in fact,
known--a housing 11 with a coil 12, integrated therein, with coil
windings 13. In order to attain as good as possible a guidance of
the magnetic flux for the inductive energy transfer, the coil unit
6 has a flux guide unit in accordance with the invention, which is
also integrated into the housing 11, in the form of a circular
ferrite plate 14. Since the material of the ferrite plate 14, which
is a good magnetically conducting material, is rather heavy, the
ferrite plate 14 forms a massive and rigid object. Since the coil
unit 6 is essentially placed parallel to the surface of the vehicle
bottom 4 and exhibits a great inertia because of its heavy weight,
the danger, in case of a rear-end collision, is that the ferrite
plate 14 is hurled in the direction of the impact site and thereby
destroys the coil unit 6 and perhaps travels from its anchorage on
the vehicle bottom 4. Since the ferrite plate 14 is also very
rigid, it also transfers--in the case of an impact--the impact
energy in its longitudinal direction L, more or less
undiminished.
[0029] It is precisely when using the coil unit 6 in electric
vehicles that measures must therefore be taken so that in case of
an accident, especially a rear-end collision, the ferrite plate 14,
if possible, causes no damage or only slight damage, and, if
possible, does not pass on undiminished impact energy, but rather,
if possible, absorbs a large amount of the impact energy.
[0030] In this regard, the invention makes provision so that the
ferrite plate 14 has material weaknesses which, in particular, with
a rear-end collision, provide for the targeted breakage of the
ferrite plate 14, wherein the impact energy is absorbed, and/or
parts of the ferrite plate 14 can move against one another so much
that the impact energy is not passed on directly, but rather the
energy flow is interrupted.
[0031] In the embodiment of the invention shown in FIGS. 1 and 2,
the ferrite plate 14 essentially has, as material weaknesses,
grooves 15, running transverse to the longitudinal direction L. The
grooves 15 or the crosslinks 16 of the ferrite plate 17 remaining
there are particularly used, in case of a collision, as
predetermined breaking points, where the ferrite plate 14 breaks in
a defined manner. As shown in FIGS. 1 and 2, in a preferred
embodiment, the grooves 15 are arranged on different flat sides 17,
18 of the ferrite plate 14, so that the ferrite plate 14 easily
breaks in the case of a collision, since the frontally introduced
impact energy is conducted, at an incline, via the crosslinks 16,
wherein a fraction of the impact energy running in the longitudinal
direction L then leads to the zigzag breaking of the ferrite plate
14. In this way, not only the direct passing on of the impact
energy is reduced, but rather the individual broken parts of the
ferrite plate then escape laterally.
[0032] In an embodiment of the invention shown in FIG. 3, the
ferrite plate 14 has breaks 19, running transverse to the
longitudinal direction L--that is, it is subdivided so that the
result is four plate parts 14a-d. In order to reduce the
disadvantages of the breaks 19 for the magnetic flux guidance
through the thus produced material break or even the air gap,
provision can be advantageously made so that impact sites between
adjacent partial elements 14a-d are very narrow--that is, for
example, the impact sites are pressed against one another by a
mechanical holding device. Alternatively, by the casting of the
plate parts 14a-d, preferably pressed against one another during
the casting process, a good magnetically conducting connection can
also be attained in the housing 11, and a high magnetic resistance,
in particular, an air gap, can be prevented.
[0033] Alternatively or additionally, the breaks 19 can also be
advantageously filled with an adhesive or bonding material, which
is preferably elastic, and in case of a collision, can be easily
destroyed, for example, rubber or a soft-elastic plastic.
Preferably, the adhesive or the bonding material can have a good
magnetic conductance, for example, by the addition of an additive
with a good magnetic conductance, such as ferrite powder. In a
favorable continuation of the invention, the adhesive or the
bonding material can have a poor electric conductance, so as to
reduce or completely prevent any eddy currents from appearing in
the ferrite plate 14.
[0034] In order to further improve the desired break behavior of
the ferrite plate 14, the embodiment of the invention shown in
FIGS. 4 and 5 provide for the provision of inclined breaks 20,
running at an incline to the plane E, instead of the breaks 19 from
FIG. 3, in the longitudinal direction L, running perpendicular to
the plane E of the ferrite plate 14. These inclined breaks 20 can
also be designed in such a way that they do not divide the ferrite
plate 14 into individual partial elements 14a-d, but rather that
the ferrite plate 14 remains, partially or completely, also
connected to the inclined breaks 20, via crosslinks similar to the
embodiment shown in FIG. 1.
[0035] Preferably, the inclined breaks 20 are so inclined that with
a collision of FIG. 6, to the left, indicated in FIG. 6 with the
large arrow, the inner plates 14b and 14c, closer to the center,
slide toward the traveling lane 2 and away from the vehicle bottom
4, if they are pushed together by the front most plate part 14a
and, perhaps, the plate part 14d furthest in the rear. This ensures
that in the case of an accident, the ferrite plate 14 or one or
more of its plate parts 14a-d are, if possible, not pushed toward
the electric vehicle 5 and, in the worst case, into its passenger
space.
[0036] In another advantageous development of the invention
according to FIG. 6, provision can also be made to incorporate a
protection element 21 into the housing 11; this additionally
prevents that, in case of destruction, the ferrite plate 14 or its
plate parts 14a-d can also not get from the housing 11 to the
outside of the vehicle 5, so as not to endanger the outside area of
the vehicle. Preferably, the protection element 21 can be produced
from a material which does not impair the magnetic and/or electric
characteristics of the coil unit 6, for example, a preferably flat
Kevlar or aramid fabric or paper.
[0037] In FIGS. 7a-c and 8a-c, schematic top views of other coil
units, in accordance with the invention, with a circular
disk-shaped or square ferrite plate 14 are shown, wherein the
invention can also be implemented with other configurations, for
example, rectangular, octagonal, polygonal, etc. With these
drawings, it is assumed that the forward traveling direction and
the longitudinal direction of the electric vehicle 5 point to the
left, as defined in FIG. 1.
[0038] In the embodiments according to FIGS. 7a and 8a, material
weaknesses 22 and 23 run in the shape of rays from the center of
the ferrite plate 14 to the outside, wherein the material
weaknesses 22 completely interrupt the ferrite plate 14, including
its thickness, whereas the material weaknesses 23 do not extend to
the periphery of the ferrite plate 14. In these embodiments, the
material weaknesses 22, 23 essentially run in the main direction of
the magnetic flux, which is produced, in the embodiment shown in
FIG. 7a, by nondepicted coil windings 13, arranged in the form of a
spiral on the ferrite plate 14, and, in the embodiment shown in
FIG. 8a, by nondepicted coil windings 13, arranged in the form of a
spiral in the square.
[0039] In the embodiments according to FIGS. 7b and 8b, material
weaknesses 24 and 25 run in a circular or square shape--that is,
interrupt the main direction of the magnetic flux. If the material
weaknesses 24 and 25, as indicated in FIGS. 7b and 8b, are complete
breaks of the ferrite plate 14, then they can be filled with an
adhesive or bonding material, described above in FIG. 3, so as to
reduce its magnetic resistance. In this way, the break behavior of
the ferrite plate 14 can be improved in the case of an inclined or
lateral rear-end accident, so that the ferrite plate 14, if
possible, breaks in the transverse direction to the rear-end
collision.
[0040] In the embodiment of the invention according to FIG. 7c,
material weaknesses 26 run in the shape of rays and not entirely to
the periphery of the ferrite plate 14, similar to the embodiment
shown in FIG. 8a, wherein in FIG. 7c, the material weaknesses 26
only break the ferrite plate 14 linearly.
[0041] An embodiment of the invention shown in FIG. 8c corresponds
to the embodiment shown in FIG. 3, with the difference that the
ferrite plate 14 is square here and not round.
[0042] Instead of the material weaknesses, described above and
shown in the figures, in the form of grooves or complete breaks,
the material weaknesses can also be designed differently, for
example, by holes, stampings, or embossings, extending, completely
or partially, through the thickness of the ferrite plate 14. Also,
the material weaknesses can be advantageously produced by
deliberately caused inhomogeneities of the material forming the
ferrite plate 14, so that, for example, the thickness of the
ferrite plate 14 remains the same at the points of the desired
material weaknesses, but the density of the material is reduced.
Also, the different types of material weaknesses can be combined
with one another.
LIST OF REFERENCE SYMBOLS
[0043] 1 Energy transfer device
[0044] 2 Lane bottom
[0045] 3 Primary coil unit
[0046] 4 Bottom of the electric vehicle
[0047] 5 Electric vehicle
[0048] 6 Secondary coil unit
[0049] 7 Primary coil housing
[0050] 8 Primary coil
[0051] 9 Primary coil windings of the primary coil
[0052] 10 Flux guide unit of the primary coil unit
[0053] 11 Housing of the secondary coil
[0054] 12 Secondary coil
[0055] 13 Coil windings of the secondary coil unit
[0056] 14 Ferrite plate as a flux guide unit of the secondary coil
unit
[0057] 15 Grooves
[0058] 16 Crosslinks
[0059] 17 Upper, inner flat side
[0060] 18 Lower, outer flat side
[0061] 19 Breaks
[0062] 20 Inclined breaks
[0063] 21 Protection element
[0064] 22 Ray-shaped material weaknesses
[0065] 23 Ray-shaped material weaknesses
[0066] 24 Circular material weaknesses
[0067] 25 Square-shaped material weaknesses
[0068] 26 Ray-shaped, linear material weaknesses
* * * * *